Colin Fitzgerald is stepping down as head of Fidelity Worldwide Investment’s institutional business, five months after taking over from his predecessor Chris McNickle.

Prior to joining Fidelity Worldwide Fitzgerald led international marketing at sister company Pyramis Global Advisors. He is leaving following the merger of the marketing divisions of the two firms under Fidelity Worldwide's lead.

According to a Fidelity Worldwide spokeswoman: “Colin Fitzgerald has decided that, having overseen this transition, now is an appropriate time to move on and seek fresh challenges. Colin’s departure will not affect any clients that transitioned their servicing from Pyramis Global Advisors to Fidelity.”

She declined to comment on his destination. Fitzgerald was not available for comment.

The spokeswoman said Jeff Lagarce retains overall responsibility for the institutional and DC businesses. Nick Birchall’s responsibilities as head of Fidelity’s UK institutional business will expand to include leadership of consultant teams.

Pyramis managed $203 billion for 667 clients at the end of last year. It was split out of Fidelity in 2005 to handle its institutional business. Pyramis handed back its marketing function outside North America to Fidelity Worldwide last year. Pyramis’s website confirms its managers can also access Fidelity’s global research initiative.

Pyramis’s marketing move, together with Fitzgerald’s departure, has reignited speculation among rival managers that Fidelity and Pyramis will get back together at some point. But the Fidelity Worldwide spokesman said there were no plans to do this.